<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div></div>
    <script>
        console.log(location.search); //?uname=andy
        // 1. 先去掉？ substr('起始的位置',截取几个字符)
        var params = location.search.substr(1); // uname=andy
        console.log(params);
        // 2. 利用=把字符串分割为数组 split('=');
        var arr = params.split('=');
        console.log(arr);
        // 3. 把数据写入div中
        var div = document.querySelector('div');
        div.innerHTML = arr[1] + '欢迎您';
    </script>
</body>

</html>